Ground-based radar atmospheric parameter correction method based on meteorological parameter correction

Abstract

The present invention discloses a method for correcting atmospheric parameters of a ground-based radar based on meteorological parameter correction, including determining a reference point according to the range bin of the ground-based radar, obtaining the temperature of the mercury thermometer and the electronic meteorological data at the reference point and constructing a temperature correction model, calculating the first atmospheric phase according to the electronic meteorological data and determining a stable reference point, obtaining the corrected temperature of the stable reference point from the temperature correction model, constructing a relative humidity correction model according to the corrected temperature and obtaining the corrected relative humidity, performing atmospheric compensation according to the corrected temperature and the corrected relative humidity, and determining the micro-deformation of the target point according to the atmospheric compensation result. This method can not only improve the accuracy of the method for correcting atmospheric parameters of a ground-based radar, obtain high-precision and reliable micro-deformation data, but also has good interpretability, which is of great significance for the structural health assessment of buildings.

Description

Technical Field

[0001] The present invention relates to the field of parameter correction, and particularly to a method for correcting atmospheric parameters of a ground-based radar based on meteorological parameter correction. Background Art

[0002] The ground-based radar has the advantages of non-contact, high precision, high sampling frequency and overall dynamic monitoring. This system can observe the movement of active deformable bodies in real time, effectively solve the deficiencies of traditional deformation monitoring technologies in terms of measurement range, monitoring distance, accuracy and environmental adaptability. With the continuous development of the ground-based radar in deformation monitoring work, its accuracy has been continuously improved. In the case of almost unchanged atmospheric environment, the observation accuracy reaches the sub-millimeter level.

[0003] However, in the actual environment, the atmospheric environment is changeable. During the propagation of electromagnetic waves in the atmosphere, the atmospheric medium will cause refraction of the propagation direction, resulting in problems such as propagation time delay and propagation path bending, thereby generating atmospheric phase errors, leading to a measurement error of the radar reaching the centimeter level, seriously affecting the accuracy of deformation monitoring results. Therefore, atmospheric correction is a necessary link to ensure monitoring accuracy.

[0004] The present invention takes the temperature data collected by a mercury thermometer as a reference, corrects the data collected by an electronic weather instrument, establishes a temperature correction model, uses the meteorological data of stable reference points in the monitoring field of view to establish a relative humidity correction model, and finally performs atmospheric compensation using the corrected temperature and relative humidity data, calculates the micro-deformation of the target point of the ground-based radar, and proposes a method for correcting atmospheric parameters of the ground-based radar based on meteorological parameter correction to overcome the deficiencies of existing optimization and adjustment methods. This method can significantly improve the accuracy of the atmospheric parameter correction method, thereby enhancing the credibility of the data collected by the ground-based radar and realizing the long-term assessment of the structural health of buildings. Summary of the Invention

[0005] The object of the present invention is to provide a method for correcting atmospheric parameters of a ground-based radar based on meteorological parameter correction.

[0006] To achieve the above object, the present invention is implemented according to the following technical solution:

[0007] The present invention includes the following steps:

[0008] Determine a reference point according to the distance bin of the ground-based radar, and obtain the temperature of the mercury thermometer and the electronic meteorological data of the reference point; the electronic meteorological data includes the temperature of the electronic weather instrument, relative humidity and atmospheric pressure;

[0009] Construct a temperature correction model according to the temperature of the mercury thermometer and the electronic meteorological data;

[0010] Calculate the first atmospheric phase based on the electronic meteorological data, determine the stable reference point according to the first atmospheric phase, and input the temperature of the electronic meteorological instrument at the stable reference point into the temperature correction model to obtain the corrected temperature;

[0011] Construct a relative humidity correction model based on the corrected temperature, and input the relative humidity at the stable reference point into the relative humidity correction model to obtain the corrected relative humidity;

[0012] Perform atmospheric compensation based on the corrected temperature and the corrected relative humidity, and determine the micro-deformation of the target point according to the atmospheric compensation result.

[0013] Furthermore, the method for constructing the temperature correction model includes:

[0014] Set the thermal signal-to-noise ratio threshold to screen the reflection points to obtain the reference points, and obtain the temperature of the mercury thermometer and the electronic meteorological data at the reference points;

[0015] Divide the temperature data into a training set and a test set; the temperature data is specifically the temperature of the mercury thermometer and the temperature of the electronic meteorological instrument n is the number of collected temperatures;

[0016] Determine the order m of the temperature correction model according to the Bayesian information criterion, m < n, and construct an m + 1 order temperature correction model. The expression is:

[0017]

[0018] where is the corrected temperature when the temperature of the electronic meteorological instrument is , and α j ∈{α 0 , α 1 , α 2 , …, α m} is the temperature correction model coefficient;

[0019] Determine the optimization objective function AIM 1 of the temperature correction model coefficient. The expression is:

[0020]

[0021] Input the training set data into the objective function AIM 1 to fit the temperature correction model coefficient α j . When the objective function AIM 1 is minimized, output the corresponding temperature correction model coefficient α j . Use α j to update the temperature correction model, and use the test set data to verify the temperature correction model, and output the temperature correction model.

[0022] Further, the method for determining the stable reference point includes:

[0023] Calculating the first atmospheric phase according to the reference point electronic meteorological data, and the expression is:

[0024]

[0025] where is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refraction index in the monitoring environment at time t, is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t;

[0026] Performing secondary screening on the reference point according to the first atmospheric phase to obtain the stable reference point, and the screening condition is:

[0027]

[0028] where is the interference phase corresponding to the phase collected by the ground-based radar at time t and S is an unbiased estimator.

[0029] Further, the method for obtaining the corrected relative humidity includes:

[0030] Determining the relative humidity correction model, and the expression is:

[0031] g(RH t ) = β 0 + β 1 RH t + β 2 (RH t ) 2

[0032] where g(RH t ) is the corrected relative humidity when the relative humidity at time t is RH t , and β 0 , β 1 , β 2 are the relative humidity correction model coefficients;

[0033] Calculating the second atmospheric phase according to the corrected temperature, the corrected relative humidity and the atmospheric pressure, and the expression is:

[0034]

[0035] where is the second atmospheric phase, is the atmospheric pressure P at time tt and the atmospheric phase calculated by correcting the temperature f(T t ); is the atmospheric phase calculated by correcting the relative humidity g(RH t ) at time t;

[0036] Determine the optimization objective function AIM of the relative humidity correction model coefficients 2 , and the expression is:

[0037]

[0038] Continuously optimize and adjust the relative humidity correction model coefficients. When the objective function AIM 2 is the smallest, output the corresponding relative humidity correction model coefficients, update and output the relative humidity correction model using the relative humidity correction model coefficients, and input the relative humidity of the stable reference point into the relative humidity correction model to obtain the corrected relative humidity.

[0039] Furthermore, the method for determining the micro-deformation of the target point includes:

[0040] Calculate the second atmospheric phase according to the corrected temperature, corrected relative humidity and atmospheric pressure Perform atmospheric compensation, and calculate the micro-deformation of the ground-based radar target point according to the atmospheric compensation result:

[0041]

[0042] where is the differential phase after atmospheric compensation, is the phase collected by the ground-based radar at time t corresponding to the interference phase, is the second atmospheric phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar.

[0043] The beneficial effects of the present invention are:

[0044] The present invention is a ground-based radar atmospheric parameter correction method based on meteorological parameter correction. Compared with the prior art, the present invention has the following technical effects:

[0045] By determining the reference point, temperature correction, screening the stable reference point, relative humidity correction and atmospheric compensation steps, the present invention can improve the accuracy of the ground-based radar atmospheric parameter correction, thereby improving the speed of the ground-based radar atmospheric parameter correction, greatly saving resources, improving the efficiency of the atmospheric parameter correction, effectively reducing the measurement error of the electronic thermometer, improving the accuracy of the temperature and relative humidity, ensuring the reliability and accuracy of the humidity data, effectively performing atmospheric compensation on the data of the target point, thereby obtaining high-precision and reliable micro-deformation data, which is of great significance for the non-contact health monitoring of building structures. Description of the Drawings

[0046] Figure 1 This is a flowchart of the steps of the ground-based radar atmospheric parameter correction method based on meteorological parameter correction of the present invention. Detailed Embodiments

[0047] The present invention will be further described below through specific embodiments. The illustrative embodiments and descriptions of the present invention are used to explain the present invention, but not to limit the present invention.

[0048] The ground-based radar atmospheric parameter correction method based on meteorological parameter correction of the present invention includes the following steps:

[0049] As Figure 1 shown, in this embodiment, it includes the following steps:

[0050] Determine a reference point according to the range bin of the ground-based radar, and obtain the temperature of the mercury thermometer and the electronic meteorological data at the reference point; the electronic meteorological data includes the temperature of the electronic meteorological instrument, relative humidity, and atmospheric pressure;

[0051] Construct a temperature correction model based on the temperature of the mercury thermometer and the electronic meteorological data;

[0052] Calculate the first atmospheric phase according to the electronic meteorological data, determine a stable reference point according to the first atmospheric phase, and input the temperature of the electronic meteorological instrument at the stable reference point into the temperature correction model to obtain the corrected temperature;

[0053] Construct a relative humidity correction model according to the corrected temperature, and input the relative humidity at the stable reference point into the relative humidity correction model to obtain the corrected relative humidity;

[0054] Perform atmospheric compensation according to the corrected temperature and the corrected relative humidity, and determine the micro-deformation of the target point according to the atmospheric compensation result.

[0055] In this embodiment, the method for constructing the temperature correction model includes:

[0056] Set a thermal signal-to-noise ratio threshold to screen the reflection points to obtain reference points, and obtain the temperature of the mercury thermometer and the electronic meteorological data at the reference points;

[0057] Divide the temperature data into a training set and a test set; the temperature data is specifically the temperature of the mercury thermometer and the temperature of the electronic meteorological instrument n is the number of temperatures collected;

[0058] Determine the order m of the temperature correction model according to the Bayesian information criterion, m < n, and construct an m + 1 order temperature correction model, the expression of which is:

[0059]

[0060] wherein is the corrected temperature when the temperature of the electronic weather instrument is , and α j ∈{α 0 , α 1 , α 2 , …, α m} are the coefficients of the temperature correction model;

[0061] Determine the optimization objective function AIM of the temperature correction model coefficients 1 , and the expression is:

[0062]

[0063] Input the training set data into the objective function AIM 1 to fit the temperature correction model coefficients α j . When the objective function AIM 1 is minimized, output the corresponding temperature correction model coefficients α j . Use α j to update the temperature correction model, use the test set data to verify the temperature correction model, and output the temperature correction model;

[0064] In actual evaluation, taking the building structure deformation monitoring in a certain area as an example, select the reflection points with a thermal signal-to-noise ratio greater than 30 dB as the reference points, screen 10 reference points, and obtain the mercury thermometer temperature and electronic weather data of the reference points at a certain moment (mercury thermometer temperature / °C, electronic weather instrument temperature / °C, relative humidity / %, atmospheric pressure / hPa): (20.1, 20.5, 40, 1010), (20.3, 20.6, 42, 1008), (20.2, 20.4, 41, 1009), (20.4, 20.7, 43, 1011), (20.0, 20.4, 40, 1010), (20.3, 20.5, 42, 1009), (20.2, 20.4, 40, 1010), (20.4, 20.6, 43, 1012), (20.1, 20.4, 38, 1008), (20.3, 20.5, 41, 1011);

[0065] According to the Bayesian information criterion, determine that the order of the temperature correction model is 2, construct a third-order temperature correction model, and obtain the optimized coefficients α 0 = 0.2, α 1 = 0.9, α 2 = 0.005 through training with the collected data.

[0066] In this embodiment, the method for determining the stable reference points includes:

[0067] Calculate the first atmospheric phase based on the reference point electronic meteorological data, and the expression is:

[0068]

[0069] Where is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refraction index in the monitoring environment at time t, is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t;

[0070] Perform secondary screening on the reference points according to the first atmospheric phase to obtain stable reference points, and the screening conditions are:

[0071]

[0072] Where is the interference phase corresponding to the phase collected by the ground-based radar at time t, and S is an unbiased estimator;

[0073] In actual evaluation, the monitoring distance of the ground-based radar is 100m, and the wavelength of the electromagnetic wave emitted by the radar is 0.1m. The first atmospheric phases of 10 reference points calculated according to the reference point electronic meteorological data are: 6283.2, 6350.1, 6300.5, 6400.3, 6250.2, 6320.6, 6280.4, 6450.7, 6230.8, 6380.5 (unit: radian), and the interference phases corresponding to the phases collected by the ground-based radar at 10 reference points are 6283.3, 6350.7, 6300.7, 6401.2, 6250.4, 6321.4, 6280.7, 6451.3, 6231.6, 6381.7 (unit: radian). When the thermal signal-to-noise ratio of the reference point is greater than 30dB, that is, under the condition of high signal-to-noise ratio, the unbiased estimator is taken as 0.2rad. Perform secondary screening on the reference points according to the first atmospheric phase to determine that the 1st, 3rd, 5th, and 7th reference points are stable reference points.

[0074] In this embodiment, the method for obtaining the corrected relative humidity includes:

[0075] Determine the relative humidity correction model, and the expression is:

[0076] g(RH t ) = β 0 + β 1 RH t + β 2 (RHt ) 2

[0077] where g(RH t ) is the corrected relative humidity at time t when the relative humidity is RH t , and β 0 , β 1 , β 2 are the coefficients of the relative humidity correction model;

[0078] Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity, and atmospheric pressure. The expression is:

[0079]

[0080] where is the second atmospheric phase, is the atmospheric pressure P at time t t and the atmospheric phase calculated from the corrected temperature f(T t ), is the atmospheric phase calculated from the corrected relative humidity g(RH t ) at time t;

[0081] Determine the optimization objective function AIM 2 of the relative humidity correction model coefficients. The expression is:

[0082]

[0083] Continuously optimize and adjust the relative humidity correction model coefficients. When the objective function AIM 2 is minimized, output the corresponding relative humidity correction model coefficients, update and output the relative humidity correction model using the relative humidity correction model coefficients, and input the relative humidity of the stable reference point into the relative humidity correction model to obtain the corrected relative humidity;

[0084] In the actual evaluation, input the temperatures of the electronic meteorological instruments at reference points 1, 3, 5, and 7 into the temperature correction model to obtain the corrected temperatures 20.3, 20.4, 20.2, and 20.4 (unit: °C). Optimize the correction model coefficients from the corrected temperature, relative humidity, and atmospheric pressure to the coefficients β 0 = 10, β 1 = 0.9, β 2 = -0.003. Input the relative humidities of reference points 1, 3, 5, and 7 into the humidity correction model to obtain the corrected relative humidity temperatures 41.2%, 41.9%, 40.5%, and 41.2%.

[0085] In this embodiment, the method for determining the micro-deformation of the target point includes:

[0086] Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity, and atmospheric pressure Perform atmospheric compensation and calculate the micro-deformation of the ground-based radar target point based on the atmospheric compensation result:

[0087]

[0088] Where is the differential phase after atmospheric compensation, is the phase collected by the ground-based radar at time t the corresponding interference phase, is the second atmospheric phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar;

[0089] In actual evaluation, a monitoring target point is selected, and the electronic meteorological data of the target point is obtained as 20.3°C, 40.2%, 1010 hPa. After correction by the temperature correction model and humidity correction model, the meteorological data is 20.5°C, 41.3%, 1010 hPa. The calculated second atmospheric phase is 6280.5 rad, the interference phase corresponding to the phase collected by the ground-based radar is 6280.55 rad, the calculated differential phase after atmospheric compensation is 0.5 rad, and the micro-deformation of the ground-based radar target point is calculated to be 0.01963495 mm according to the atmospheric compensation result.

[0090] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction, characterized in that: It includes the following steps: S1. Determine a reference point according to the range bin of the ground-based radar, and obtain the temperature of the mercury thermometer and the electronic meteorological data of the reference point; the electronic meteorological data includes the temperature of the electronic meteorological instrument, relative humidity, and atmospheric pressure; S2. Construct a temperature correction model based on the temperature of the mercury thermometer and the electronic meteorological data; S3. Calculate the first atmospheric phase according to the electronic meteorological data, determine a stable reference point according to the first atmospheric phase, and input the temperature of the electronic meteorological instrument of the stable reference point into the temperature correction model to obtain a corrected temperature; S4. Construct a relative humidity correction model according to the corrected temperature, and input the relative humidity of the stable reference point into the relative humidity correction model to obtain a corrected relative humidity; S5. Perform atmospheric compensation according to the corrected temperature and the corrected relative humidity, and determine the micro-deformation of the target point according to the atmospheric compensation result.

2. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for constructing the temperature correction model includes: Set a thermal signal-to-noise ratio threshold to screen the reflection points to obtain reference points, and obtain the temperature of the mercury thermometer and the electronic meteorological data of the reference points; The temperature data is divided into a training set and a test set; the temperature data is specifically the mercury thermometer temperature and electronic weather instrument temperature n is the number of temperatures collected; Determine the order m of the temperature correction model according to the Bayesian information criterion, where m < n, and construct an m + 1 order temperature correction model, the expression of which is: in The temperature of the electronic weather instrument is Corrected temperature at j ∈{α0,α1,α2,…,α m } is the temperature correction model coefficient; Determine the optimization objective function AIM1 of the temperature correction model coefficients, the expression of which is: Input the training set data into the objective function AIM1 to fit the temperature correction model coefficient α j When the objective function AIM1 is minimum, the corresponding temperature correction model coefficient α is output j , using α j Update the temperature correction model, use the test set data to verify the temperature correction model, and output the temperature correction model.

3. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for determining the stable reference point includes: Calculate the first atmospheric phase according to the electronic meteorological data of the reference point, the expression of which is: in is the first atmospheric phase, λ is the wavelength of the electromagnetic wave emitted by the ground-based radar, r is the monitoring distance of the target point from the radar, N is the atmospheric refractive index in the monitoring environment at time t, is the temperature of the electronic meteorological instrument at time t, P t is the atmospheric pressure at time t, RH t is the relative humidity at time t; Perform secondary screening on the reference points according to the first atmospheric phase to obtain stable reference points, and the screening condition is: in is the ground-based radar acquisition phase at time t The corresponding interference phase, S is an unbiased estimator.

4. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 3, characterized in that: The method for obtaining the corrected relative humidity includes: Determine the relative humidity correction model, the expression of which is: g(RH t )=β0+β1RH t +β2(RH t ) 2 Where g(RH t ) is the relative humidity at time t, RH t Corrected relative humidity at , β0, β1, β2 are relative humidity correction model coefficients; Calculate the second atmospheric phase according to the corrected temperature, the corrected relative humidity, and the atmospheric pressure, the expression of which is: in is the second atmospheric phase, is the atmospheric pressure P at time t t and the corrected temperature f(T t ) calculated atmospheric phase, is the corrected relative humidity at time t g(RH t ) calculated atmospheric phase; Determine the optimization objective function AIM2 of the relative humidity correction model coefficients, the expression of which is: Continuously optimize and adjust the coefficients of the relative humidity correction model. When the objective function AIM2 is minimized, output the corresponding coefficients of the relative humidity correction model, update and output the relative humidity correction model using the coefficients of the relative humidity correction model, and input the relative humidity of the stable reference point into the relative humidity correction model to obtain the corrected relative humidity.

5. The method for correcting atmospheric parameters of ground-based radar based on meteorological parameter correction according to claim 1, characterized in that: The method for determining the micro-deformation of the target point includes: Calculate the second atmospheric phase based on the corrected temperature, corrected relative humidity and atmospheric pressure Perform atmospheric compensation and calculate the micro deformation of the ground-based radar target point based on the atmospheric compensation result: in is the differential phase after atmospheric compensation, is the ground-based radar acquisition phase at time t The corresponding interference phase, is the second atmospheric phase, Δd is the micro-deformation of the ground-based radar target point, and λ is the wavelength of the electromagnetic wave emitted by the ground-based radar.

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